(1) Field of the Invention
The present invention relates to the transmission of rotational moments between a drive shaft and a driven shaft. More specifically, this invention is directed to universal joints and particularly to improved constant velocity universal joints with ball bearing races. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
(2) Description of the Prior Art
Universal joints for use in delivering torque from a drive shaft to a tubular axle are well known in the art. In the prior art universal joints, ball bearing races are inserted in the joint assembly in the interest of insuring uniform and constant velocity in the transmission of moments; the coupling of torque between the drive and driven shafts being through bearing races which are symmetrical with the joint. Thus, the prior art universal joints are comprised of a plurality of components. In manufacture, the bearing race defining members are separately formed and thereafter installed in the "housing" defining joint portions; the housing defining portions or members typically being integral with the drive and driven shafts. The drive and/or driven shafts may be of tubular constructions in the interest of reducing the weight of the assembly.
The above briefly described prior art universal joints have a number of inherent disadvantages. Perhaps the most significant of these disadvantages resides in the fact that the previous universal joints are comparatively expensive as a result of the fact that a plurality of components must be separately manufactured and thereafter assembled to define the joint. Additionally, the structure of the prior art universal joints requires that a manufacturer or service facility stock spare parts for each of the plurality of joint defining components. As a further disadvantage, the use of a plurality of assembled components to define a universal joint increases the weight of the joint and thus has a deleterious effect at high rmp's; especially in motor vehicle drive train utilization. Thus, drive trains employing conventional prior art universal joints, due to the comparatively large mass of such joints, exhibit wear as a result of the high centrifugal and inertial forces encountered during operation; this being particularly true during deceleration. It is also to be observed that conventional prior art universal joints are known to exhibit comparatively high wear due to their own natural frequency of vibration.
Some prior art drive trains employ universal joints wherein the maximum outer diameter of the joint is approximately equal to the outer diameter of the drive shaft. While such a configuration may have the atttribute of facilitating assembly, this arrangement requires space which may not be available; especially in motor vehicles. In addition, the larger diameter drive shafts required in such assemblies develop greater centrifugal and inertial forces which are known to result in increased wear during decelerations.